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CVE-2026-16621 - Before 9 Plugin

CVE-2026-16621

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying.

CVE-2026-16621

MEDIUM CVSS 5.3 Published 2026-08-12 Updated 2026-08-12
AI Risk Elevated (60/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P3 Priority
Severity Band MEDIUM
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected Components 2
Reference Links 1
AI Risk Engine Elevated (60/100)
Exploitability High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-08-12 CVE published and first recorded in the threat feed.
  2. 2026-08-12 Record updated with latest vulnerability metadata.
  3. 2026-08-12 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 1 hour ago

AI enriched 1 hour ago (2026-08-12 17:39 UTC)

Technical Summary

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying.

Potential Impact

Severity is MEDIUM (CVSS 5.3). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 60/100 (Elevated, High) with priority P3 Priority. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

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